tyres for my clueless friend

I have a friend named David who is a total antisocial freak. David is a great guy but he does not really like to talk with people. From what I know I am basically the only person David talks with. He picks his friends carefully. As a matter of fact, he does not pick them at all because he is a true outsider. He rarely meets new people. I met him on a party where he, as it later turned out, was not suppose to be. He appeared on that party only because he HAD to borrow something from his neighbor who basically was my good friend. When he wanted to borrow that item he was basically forced to stay and have fun. I remember David sitting in the corner doing nothing in particular. I remember him drinking cocktails, I guess. A few hot women wanted to dance with him but he refused and rejected all of them. I then thought "what a strange guy" and went to talk to him. He was extremely repulsive and he wanted to repel me with all costs. He did not want to talk to me at all, however, I convinced him to and we become good friends from there on. Now I have to help him in many different cases like yesterday. I had to help him buy tyres for his car because he did not feel like talking to the guys at a tyres store. I mean, I like him and all but this gets pretty annoying at times.